When I ride, I never wear cable ties, instead I listen to the Chirp of the magpie, they make a sound before they attack, the sound is very loud, I listen to my rock music in my headphones and still hear it. Here's what to do when you hear the chirp:
1. Pause your music
2. Locate the Magpies with your eyes
3. Get of the bike and walk it
4. While walking stare at the magpie the whole time, DO NOT take your eyes of it.
5. When your 50-80m away from it, get back on your bike slowly and ride